A Wide Area Network (WAN) is a network that spans a large geographic area, often using leased telecommunication lines to connect multiple LANs or MANs.

Elaboration:

Unlike LANs, which are limited to small areas, WANs connect cities, countries, or even continents. They rely on:

• Fiber optics, satellites, leased lines (MPLS), and VPNs for connectivity.
• ISPs (Internet Service Providers) for routing and data transmission.
• Cloud computing and remote access for businesses with global operations.

Example:

• The internet (the largest WAN).
• A multinational company connecting its offices in New York, London, and Tokyo via private WAN links.

WANs often face issues like latency, security risks, and high costs, requiring advanced networking solutions.